Assembly for a Drug Delivery Device and Drug Delivery Device

ABSTRACT

An assembly for a drug delivery device ( 1 ) is proposed, comprising a housing ( 13 ) having a proximal end and a distal end, a dose member ( 23 ) which is displaceable in the proximal direction with respect to the housing for setting of a dose of a drug, a clutch member ( 28 ) which is displaced in the proximal direction with respect to the housing when setting the dose, and a stop member ( 30 ) configured to define a clutch stop position for the proximal displacement of the clutch member with respect to the housing, with the clutch member, when in the clutch stop position, being prevented from further displacement in the proximal direction with respect to the housing, 
     wherein the clutch member and the dose member are configured to mechanically cooperate with one another when the clutch member is in the clutch stop position, thereby preventing further displacement of the dose member in the proximal direction with respect to the housing during setting of the dose. Furthermore, a drug delivery device ( 1 ) is proposed.

The present disclosure relates to an assembly for a drug delivery deviceand a drug delivery device.

Drug delivery devices may be used for self-administration of a drugcontained in the device by a patient. For this purpose, the user may seta dose of drug to be delivered and deliver the dose subsequently. As theamount of drug present in the device may be limited, it may occur thatthe user sets a desired dose which exceeds the actually available amountof drug in the device. Accordingly, if the user administers this setdose, the user might be of the wrong opinion that the desired amount wasadministered.

It is an object of the present disclosure to provide for an assemblythat facilitates provision of an improved drug delivery device and adrug delivery device comprising such an assembly.

This object is achieved by an assembly according to the independentclaim. Advantageous embodiments and refinements may be the subjectmatter of dependent claims.

According to one aspect, an assembly for a drug delivery devicecomprises a housing having a proximal end and a distal end, a dosemember which is displaceable in the proximal direction with respect tothe housing for setting of a dose of a drug, a clutch member which isdisplaced in the proximal direction with respect to the housing whensetting the dose and a stop member configured to define a clutch stopposition for the proximal displacement of the clutch member with respectto the housing, with the clutch member, when in the clutch stopposition, being prevented from further displacement in the proximaldirection with respect to the housing. Preferably, the clutch member andthe dose member are configured to mechanically cooperate with oneanother when the clutch member is in the clutch stop position, thereby,in particular during mechanical cooperation, preventing furtherdisplacement of the dose member in the proximal direction with respectto the housing, in particular during setting of the dose.

A drug delivery device expediently comprises an assembly as describedabove. The drug delivery device may comprise a cartridge containing adrug. The cartridge may have a proximal end and a distal end. A pistonmay be retained within the cartridge. The piston may close the cartridgeproximally. The piston is preferably displaceable in the distaldirection with respect to the cartridge for dispensing a dose of thedrug from the cartridge. The assembly is preferably an end stopassembly. The end stop assembly may prevent setting of a desired dose ofthe drug, which desired dose would exceed the amount of drug which iscurrently available in the cartridge for delivery. The position of thestop member with respect to the distal end of the cartridge may beindicative of the amount of drug currently available in the cartridge.As one or more doses of the drug are dispensed from the cartridge, thestop member may successively be displaced towards the distal end of thecartridge, thereby indicating that less drug is left in the cartridge.

As the drug delivery device preferably comprises an assembly asdescribed above, features which are described in connection with thedrug delivery device may also apply for the assembly and vice versa.

Accordingly, by means of the assembly, setting of a dose of the drugwhich exceeds the actually available amount of drug may be prevented onaccount of the clutch member mechanically cooperating with the dosemember, for example by engagement. Thereby, the risk of administering anamount of drug which is less than the set dose is reduced. Duringmechanical cooperation, an engagement member of the clutch member mayengage an engagement feature of the dose member.

The term “drug”, as used herein, means a pharmaceutical formulationcontaining at least one pharmaceutically active compound,

wherein in one embodiment the pharmaceutically active compound has amolecular weight up to 1500 Da and/or is a peptide, a proteine, apolysaccharide, a vaccine, a DNA, a RNA, a antibody, an enzyme, anantibody, a hormone or an oligonucleotide, or a mixture of theabove-mentioned pharmaceutically active compound,

wherein in a further embodiment the pharmaceutically active compound isuseful for the treatment and/or prophylaxis of diabetes mellitus orcomplications associated with diabetes mellitus such as diabeticretinopathy, thromboembolism disorders such as deep vein or pulmonarythromboembolism, acute coronary syndrome (ACS), angina, myocardialinfarction, cancer, macular degeneration, inflammation, hay fever,atherosclerosis and/or rheumatoid arthritis,

wherein in a further embodiment the pharmaceutically active compoundcomprises at least one peptide for the treatment and/or prophylaxis ofdiabetes mellitus or complications associated with diabetes mellitussuch as diabetic retinopathy,

wherein in a further embodiment the pharmaceutically active compoundcomprises at least one human insulin or a human insulin analogue orderivative, glucagon-like peptide (GLP-1) or an analogue or derivativethereof, or exedin-3 or exedin-4 or an analogue or derivative ofexedin-3 or exedin-4.

Insulin analogues are for example Gly(A21), Arg(B31), Arg(B32) humaninsulin; Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) humaninsulin; Asp(B28) human insulin; human insulin, wherein proline inposition B28 is replaced by Asp, Lys, Leu, Val or Ala and wherein inposition B29 Lys may be replaced by Pro; Ala(B26) human insulin;Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) humaninsulin.

Insulin derivates are for example B29-N-myristoyl-des(B30) humaninsulin; B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl humaninsulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin;B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30human insulin; B29-N-(N-palmitoyl-Y-glutamyl)-des(B30) human insulin;B29-N-(N-lithocholyl-Y-glutamyl)-des(B30) human insulin;B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin andB29-N-(ω-carboxyheptadecanoyl) human insulin.

Exendin-4 for example means Exendin-4(1-39), a peptide of the sequenceH-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.

Exendin-4 derivatives are for example selected from the following listof compounds:

H-(Lys)4-des Pro36, des Pro37 Exendin-4(1-39)-NH2,

H-(Lys)5-des Pro36, des Pro37 Exendin-4(1-39)-NH2,

des Pro36 [Asp28] Exendin-4(1-39),

des Pro36 [IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39); or

des Pro36 [Asp28] Exendin-4(1-39),

des Pro36 [IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39), wherein thegroup -Lys6-NH2 may be bound to the C-terminus of the Exendin-4derivative;

or an Exendin-4 derivative of the sequence

H-(Lys)6-des Pro36 [Asp28] Exendin-4(1-39)-Lys-6-NH2,

des Asp28 Pro36, Pro37, Pro38Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro38 [Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39)-Lys-6-NH2,

H-des Asp28 Pro36, Pro37, Pro38 [Trp(O2)25] Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36 [Met(O)14, Asp28] Exendin-4(1-39)-Lys-6-NH2,

des Met(O)14 Asp28 Pro36, Pro37, Pro38 Exendin-4(1-39)-NH2,

H-(Lys)6-desPro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5 des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Lys-6-des Pro36 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-Lys-6-NH2,

H-des Asp28 Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25]Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(S1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2;

or a pharmaceutically acceptable salt or solvate of any one of theafore-mentioned Exedin-4 derivative.

Hormones are for example hypophysis hormones or hypothalamus hormones orregulatory active peptides and their antagonists as listed in RoteListe, ed. 2008, Chapter 50, such as Gonadotropine (Follitropin,Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin),Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin,Buserelin, Nafarelin, Goserelin.

A polysaccharide is for example a glucosaminoglycane, a hyaluronic acid,a heparin, a low molecular weight heparin or an ultra low molecularweight heparin or a derivative thereof, or a sulphated, e.g. apoly-sulphated form of the above-mentioned polysaccharides, and/or apharmaceutically acceptable salt thereof. An example of apharmaceutically acceptable salt of a poly-sulphated low molecularweight heparin is enoxaparin sodium.

Pharmaceutically acceptable salts are for example acid addition saltsand basic salts. Acid addition salts are e.g. HCl or HBr salts. Basicsalts are e.g. salts having a cation selected from alkali or alkaline,e.g. Na+, or K+, or Ca2+, or an ammonium ion N+(R1)(R2)(R3)(R4), whereinR1 to R4 independently of each other mean: hydrogen, an optionallysubstituted C1-C6-alkyl group, an optionally substituted C2-C6-alkenylgroup, an optionally substituted C6-C10-aryl group, or an optionallysubstituted C6-C10-heteroaryl group. Further examples ofpharmaceutically acceptable salts are described in “Remington'sPharmaceutical Sciences” 17. ed. Alfonso R. Gennaro (Ed.), MarkPublishing Company, Easton, Pa., U.S.A., 1985 and in Encyclopedia ofPharmaceutical Technology.

Pharmaceutically acceptable solvates are for example hydrates.

In a preferred embodiment, the assembly comprises a clutch springmember. The clutch spring member may be configured for and, inparticular, arranged to prevent the dose member from cooperatingmechanically with the clutch member. The clutch spring member mayprevent the dose member from cooperating mechanically with the clutchmember when the clutch member is out of the clutch stop position. Theclutch spring member may bias the dose member and the clutch member awayfrom one another. In particular, the clutch spring member may keepengagement feature and engagement member at a predetermined distancewith respect to each other when the clutch member is out of the clutchstop position.

In another preferred embodiment, the dose member is rotated in a firstdirection with respect to the housing for setting of the dose of thedrug and, in particular, displaced in the proximal direction whenrotating in the first direction. The dose member may be threadedlyconnected to the housing, such as threadedly engaged with the housing oran insert thereof, for this purpose. Rotation of the dose member in thefirst direction with respect to the housing may be prevented or stoppedwhen the dose member and the clutch member cooperate mechanically.

The dose member may be displaced in the distal direction with respect tothe housing when delivering the dose and, in particular, rotate in asecond direction, opposite to the first direction when delivering thedose.

In another preferred embodiment, the clutch member is secured againstrotation with respect to the housing. The clutch member may berotationally locked with respect to the housing. During mechanicalcooperation of the dose member and the clutch member, rotationalmovement of the dose member with respect to the clutch member in thefirst direction is prevented. Rotational movement of the dose memberwith respect to the clutch member in the second direction opposite tothe first direction is expediently allowed. A uni-directional frictionclutch mechanism, which permits relative rotational movement betweendose member and clutch member in one direction only, may be formedbetween clutch member and dose member during mechanical cooperation whenthe clutch member is in the clutch stop position. When the clutch memberis out of the clutch stop position, the dose member may rotate withrespect to the clutch member in the first direction and in the seconddirection.

The clutch member may follow displacement of the dose member in theproximal direction with respect to the housing during setting of thedose. The clutch member may follow displacement of the dose member inthe distal direction with respect to the housing during delivery of thedose.

In another preferred embodiment, the stop member is displaced in thedistal direction with respect to the housing when delivering the dose ofthe drug. Thereby, the clutch stop position is preferably displaced inthe distal direction. The clutch stop position may, in particular, bedisplaced towards the clutch member. Thereby, the distance betweenclutch member and clutch stop position may be reduced. As the positionof the stop member with respect to the distal end of the housing and/orof the cartridge may be indicative of the amount of drug currentlyavailable in the cartridge, setting of a dose that exceeds the availableamount is prevented, because, before a dose exceeding the actuallyavailable amount could be set, the clutch member has already moved intothe clutch stop position and mechanically cooperates with the dosemember to prevent further proximal displacement of the dose member.Further proximal displacement of the dose member, however, would benecessary for increasing the size of the dose.

During dose setting, dose member and clutch member may be displaced inthe proximal direction from a distal initial position to a proximal endposition. The proximal end position may correspond to the size of theset dose. A maximum proximal end position may correspond to the maximumdose which may be set to be delivered by the device. Of course, themaximum dose is expediently smaller than the amount of drug initiallyprovided for in the still unused drug delivery device.

During dose delivery, the stop member may be successively driven in thedistal direction and, eventually, reach a position which is between thedistal initial position and the maximum proximal end position of theclutch member. When a subsequent dose is set, the clutch member may bestopped in the stop position, for example by abutting the stop memberduring setting of the dose, thereby preventing setting of an excessivedose which could not be delivered.

The clutch member may be connected to the dose member. A connectionmember may be provided for connecting the clutch member to the dosemember. The connection member may be provided with one or more guidefeatures that may be configured and arranged to prevent rotationalmovement of the connection member with respect to the housing. Theconnection member may be rotationally locked to the clutch member. Thus,the clutch member cannot rotate with respect to the connection member.

In another preferred embodiment, the assembly comprises a piston rod.The piston rod may be configured to be displaced in the distal directionwith respect to the housing for delivering the dose. The clutch stopposition may be displaced in the distal direction with respect to thehousing together with the piston rod. In particular, the stop member maybe integrated in or connected to the piston rod. The stop member may befirmly connected to the piston rod. The piston rod may rotate and bedisplaced in the distal direction with respect to the housing. Thepiston rod may be threadedly connected to the housing or an insertthereof, for this purpose.

The stop member and/or the piston rod is preferably secured againstdisplacement in the proximal direction during setting and/or delivery ofthe dose.

The stop member may be a protrusion of the piston rod. In particular,the stop member may be provided for by means of the distal end of a,preferably protruding, drive thread of the piston rod. The drive threadmay determine the rotation angle, by which the piston rod is rotatedwith respect to the housing when it is driven by a drive member. Thepiston rod may comprise a displacement thread. The displacement threadis preferably different from the drive thread. For example, the drivethread may be a male thread and the displacement thread may be a femalethread. Drive thread and displacement thread may have different leads.The displacement thread is expediently provided for determining thedisplacement of the piston rod with respect to the housing in the distaldirection. The displacement thread may be arranged further away from aproximal end of the piston rod than the drive thread. The drive threadmay be arranged further away from a distal end of the piston rod thanthe displacement thread.

In a further preferred embodiment, the assembly comprises a dose dialmember. The dose dial member may be rotatable in the first directionand/or displaceable in the proximal direction with respect to thehousing for setting of the dose. The dose member may follow rotationalmovement of the dose dial member and movement of the dose dial member inthe proximal direction with respect to the housing during setting of thedose. The dose dial member may be splined to the dose member duringsetting of the dose.

Further features, expediencies and advantageous refinements becomeapparent from the following description of the exemplary embodiment inconnection with the figures.

FIG. 1 shows an exemplary embodiment of a drug delivery device on thebasis of a partly sectional view.

FIG. 2 shows an exploded view of parts of the drug delivery device.

FIG. 3 shows an oblique view of an embodiment of a clutch member.

FIG. 4 shows an oblique view of an embodiment of a dose member.

FIG. 5 shows an oblique sectional view of the clutch member connected tothe dose member.

FIG. 6 shows an exploded view of parts of the drug delivery device.

FIG. 7 shows an exploded view of parts of the drug delivery device.

FIG. 8 shows an oblique sectional view of the assembled drug deliverydevice in a dose set position.

FIG. 9 shows a sectional view of a part of the assembled drug deliverydevice during dose setting.

FIG. 10 shows a sectional view of a part of the assembled drug deliverydevice during dose setting.

Like elements, elements of the same kind and identically acting elementsmay be provided with the same reference numerals in the figures.

Turning now to FIG. 1, a drug delivery device 1 comprises a cartridgeunit 2 and a drive unit 3. The cartridge unit 2 comprises a cartridge 4.A drug 5 is retained in the cartridge 4. The drug 5 is preferably aliquid drug. The cartridge 4 preferably comprises a plurality of dosesof the drug 5. The drug 5 may comprise insulin, such as a short-actingor a long-acting insulin, heparin, or growth hormones, for example. Thecartridge 4 has an outlet 6 at its distal end. Drug 5 may be dispensedfrom the cartridge through outlet 6. The device 1 may be a pen-typedevice, in particular a pen-type injector. The device 1 may be adisposable or a reusable device. The device 1 may be a device configuredto dispense fixed doses of the drug or variable, preferablyuser-settable, doses. The device 1 may be a needle-based or a needlefree device. The device 1 may be an injection device.

The term “distal end” of the drug delivery device 1 or a componentthereof may refer to that end of the device or the component which isclosest to the dispensing end of the device 1. The term “proximal end”of the drug delivery device 1 or a component thereof may refer to thatend of the device or the component which is furthest away from thedispensing end of the device. In FIG. 1, the distal end of the device 1was assigned reference numeral 7 and the proximal end of the device wasassigned reference numeral 8.

The outlet 6 may be covered by a membrane 9, which may protect the drug5 against external influences during storage of the cartridge. Themembrane 9 is expediently impermeable for the drug. For drug delivery,membrane 9 may be penetrated, e.g. pierced. For example, membrane 9 maybe pierced by a needle unit (not explicitly shown). The needle unit maybe (releasably) attached, e.g. screwed, to the distal end of thecartridge unit 2. The needle unit may provide for fluid communicationfrom the inside of the cartridge 4 to the outside of the cartridgethrough outlet 6.

A piston 10 is retained within the cartridge 4. The piston 10 is movablewith respect to the cartridge. The piston 10 may seal the drug 5 withinthe cartridge. The piston 10 expediently seals the interior of thecartridge 4 proximally. Movement of the piston 10 with respect to thecartridge 4 in the distal direction causes drug 5 to be dispensed fromthe cartridge through outlet 6 during operation of the device.

The cartridge unit 2 furthermore comprises a cartridge retaining member11. The cartridge 4 is retained within the cartridge retaining member11. The cartridge retaining member 11 may stabilize the cartridge 4mechanically. Additionally or alternatively, the cartridge retainingmember 11 may be provided with a fixing member (not explicitly shown)for attaching the cartridge unit 2 to the drive unit 3.

The cartridge unit 2 and the drive unit 3 are secured to one another,preferably releasably secured. A cartridge unit 2 which is releasablysecured to the drive unit may be detached from the drive unit 3, forexample in order to allow for providing for a new cartridge 4, if all ofthe doses of drug which once were in the cartridge formerly attached tothe drive unit 3 have already been dispensed. The cartridge retainingmember 11 may be releasably secured to the drive unit 3 via a thread,for example.

Alternatively, the cartridge retaining member 11 may be dispensed with.It is particularly expedient, in this case, to apply a robust cartridge4 and to attach the cartridge directly to the drive unit 3.

The drive unit 3 is configured for transferring force, preferablyuser-exerted force, particularly preferably manually exerted force, tothe piston 10 for displacing the piston 10 with respect to the cartridge4 in the distal direction. A dose of drug may be dispensed from thecartridge in this way. The size of the delivered dose may be determinedby the distance by which the piston 10 is displaced with respect to thecartridge 4 in the distal direction during dose delivery.

The drive unit 3 comprises a drive mechanism. The drive mechanismcomprises a piston rod 12. The piston rod 12 may be configured fortransferring force to the piston 10, thereby displacing the piston inthe distal direction with respect to the cartridge 4. A distal end faceof the piston rod 12 may be arranged to abut a proximal end face of thepiston 10. Alternatively, a bearing member (not explicitly shown) may bearranged to advance the piston 10, preferably to abut the proximal endface of the piston 10. The bearing member may be arranged between piston10 and piston rod 12. The bearing member may be fixed to the piston rod12 or may be a separate member. If the piston rod 12 is configured to berotated during operation of the device, for example during dosedelivery, it is particularly expedient to provide for a bearing member.The bearing member may be axially displaced together with the (rotating)piston rod 12 with respect to the cartridge 4. The piston rod 12 may berotatable with respect to the bearing member. In this way, the risk thatthe rotating piston rod 12 drills into the piston 10 and thereby damagesthe piston is reduced. Accordingly, while the piston rod 12 rotates andis displaced with respect to the housing, the bearing member ispreferably only displaced axially, i.e. does not rotate. The piston rod12 may be bounded by the bearing member.

The drive unit 3 comprises a housing 13 which may be part of the drivemechanism and/or house parts of the drive mechanism. The piston rod 12may be retained in the housing 13. A proximal end side 14 of thecartridge unit 2 may be secured to the drive unit 3 at a distal end side15 of the housing 13, for example via a threaded connection. Housing 13,cartridge 4 and/or cartridge retaining member 11 may have a tubularshape.

The term “housing” shall preferably mean any exterior housing (“mainhousing”, “body”, “shell”) or interior housing (“insert”, “inner body”)which may have a unidirectional axial coupling to prevent proximalmovement of specific components. The housing may be designed to enablethe safe, correct, and comfortable handling of the drug delivery deviceor any of its mechanism. Usually, it is designed to house, fix, protect,guide, and/or engage with any of the inner components of the drugdelivery device (e.g., the drive mechanism, cartridge, piston, pistonrod), preferably by limiting the exposure to contaminants, such asliquid, dust, dirt etc. In general, the housing may be unitary or amultipart component of tubular or non-tubular shape.

The term “piston rod” shall preferably mean a component adapted tooperate through/within the housing, which may be designed to transferaxial movement through/within the drug delivery device, preferably fromthe drive member to the piston, for example for the purpose ofdischarging/dispensing an injectable product. Said piston rod may beflexible or not. It may be a simple rod, a lead-screw, a rack and pinionsystem, a worm gear system, or the like. “piston rod” shall further meana component having a circular or non-circular cross-section. It may bemade of any suitable material known to a person skilled in the art andmay be of unitary or multipart construction.

The drive unit 3 comprises a dose part 16. The dose part 16 is movablewith respect to the housing 13. The dose part 16 may be movable in theproximal direction with respect to the housing 13 for setting of a doseof the drug 5 which is to be delivered and, in particular, in the distaldirection with respect to the housing for delivering the set dose. Thedose part 16 is preferably connected to the housing 13. The dose part 16may be moved (displaced) between a proximal end position and a distalend position with respect to the housing 13 (not explicitly shown). Thedistance by which the dose part 16 is displaced with respect to thehousing 13 during setting of the dose may determine a size of the dose.The (maximum) proximal end position and the distal end position of thedose part 16 may be determined by a respective stop feature which maylimit the proximal or distal travel of the dose part with respect to thehousing 13. The device 1 may be a variable dose device, i.e. a deviceconfigured for delivering doses of the drug of different, preferablyuser-settable, sizes. Alternatively, the device may be a fixed dosedevice.

The device 1 may be a manually, in particular non-electrically, drivendevice. The (user-applied) force which causes the dose part 16 to bemoved with respect to the housing 13 in the distal direction may betransferred to the piston rod 12 by the drive mechanism. For thispurpose, other elements of the drive mechanism may be provided which arenot explicitly shown in FIG. 1. The drive mechanism is preferablyconfigured not to move the piston rod 12 with respect to the housing 13when the dose part is moved in the proximal direction with respect tothe housing for setting of the dose.

Several doses of the drug 5 may be dispensed from the cartridge 4. Asthe piston 10 successively advances towards the distal end of thecartridge 4, the amount of drug remaining in the cartridge 4, which isstill available for dose delivery, is reduced. Accordingly, thesituation may arise that a user sets a desired dose of the drug 5 whichhe intends to (self-)administer, but the amount of drug still left inthe cartridge is not sufficient for delivering the desired dose. Thus,if a user is allowed to set a dose that exceeds the amount of drug leftin the cartridge, the risk of administering a wrong dose of the drug,e.g. a dose which is less than the desired dose, is increased. Ofcourse, administration of a wrong dose may have fatal, for examplelethal, consequences for the user. Thus, it is desirable to provide foran end stop mechanism, for example a safety mechanism, which preventssetting of a dose of a drug which dose exceeds the actually availableamount of drug 5 in the cartridge.

An embodiment of an end stop mechanism or end stop assembly, which issuitable for preventing setting of a dose of the drug 5 which exceedsthe amount of drug available in the cartridge for dispense is describedin conjunction with FIGS. 2 to 10 which also relate to a drug deliverydevice 1. The drug delivery device 1 illustrated therein may largelycorrespond to the device described in conjunction with FIG. 1, with thedrive mechanism and, of course, the end stop mechanism being shown inmore detail.

In the exploded view of FIG. 2, housing 13 is shown with its distal end15 and its proximal end 17. Housing 13 is preferably configured toretain further elements of the drug delivery device.

An insert member 18 is configured to be retained within housing 13.Insert member 18 may be secured against axial and rotational movementwith respect to the housing 13. On an outer surface, insert member 18may be provided with one or more fixing elements 19, for examplesnap-fit elements. Fixing elements 19 may be configured to engagecorresponding inner fixing means in the housing (not explicitly shown).Fixing elements 19 may protrude radially from insert member 18. Theinsert member 18 is provided with one or more (outer) guide members 20,which may extend axially. Guide members 20 may be provided for allowingfor inserting the insert member 18 in and/or securing it to the housing13 (only) in a predetermined orientation. Guide members 20 may engagecorresponding guide features in the housing 13 when insert member 18 isinserted in the housing 13 (not explicitly shown in FIG. 2). The insertmember 18 may be an insert sleeve, for example. The insert member 18 maycomprise a (inner) thread 21. Thread 21 may be a helical thread. One ormore (inner) guide tracks 22 may be provided by the insert member 18, inparticular on an inner surface thereof. Guide tracks 22 may interruptthread 21. Guide tracks 22 may extend axially. Instead of providing fora separate insert member 18 as illustrated, thread 21 and/or guidetracks 22 may be provided for in the housing 13.

The drug delivery device 1 comprises a dose member 23. Dose member 23 isconfigured to be displaced in the proximal direction with respect to thehousing 13 during setting of the dose of the drug 5 and/or in the distaldirection with respect to the housing during delivery of the dose. Dosemember 23 is provided with a (outer) thread 24. Thread 24 may bearranged in the distal end section of the dose member 23. Thread 24 maybe arranged to engage thread 22 of the insert member 18. Dose member 23may be a sleeve, for example. Dose member 23 may rotate in a firstdirection with respect to the housing during setting of the dose,thereby, in particular, being displaced in the proximal direction withrespect to the housing on account of the threaded engagement to theinsert member 18. During dose delivery, dose member 23 may rotate in asecond direction opposite to the first direction with respect to thehousing 13, thereby, in particular, being displaced in the distaldirection with respect to the housing. Dose member 23 may be displacedin the proximal direction during dose setting from a distal initialposition to a proximal end position and during dose delivery in thedistal direction from the proximal end position back into the initialposition.

The dose member 23 comprises one or more (outer) guide members 25, e.g.guide ribs. Guide members 25 may extend axially. Guide members 25 may bearranged in the proximal section of the dose member 23 as seen fromthread 24. Guide members 25 may be configured to engage correspondingguide slots in a dose dial member (not explicitly shown in FIG. 2, seeguide slots 50 in FIG. 7, for example). The dose member 23 and the dosedial member may be splined to one another when the device is assembled.Thus, relative rotational movement between dose member 23 and dose dialmember is prevented. Relative axial movement between dose member 23 anddose dial member is allowed.

Additionally, the piston rod 12 is shown in FIG. 2. The piston rod 12 isprovided with two different threads, displacement thread 26 and drivethread 27. Drive thread 27 may be arranged further away from the distalend of piston rod 12 than displacement thread 26. Drive thread 27 may bearranged in the proximal end section of the piston rod 12. Displacementthread 26 may be arranged in the distal end section of the piston rod12. Displacement thread 26 may determine the axial displacement of thepiston rod 12 when the piston rod 12 rotates and is axially displacedwith respect to the housing. The drive thread may, for example due tointeraction with a drive member (not explicitly shown in FIG. 2)determine the rotation angle by which the piston rod 12 is rotated.Displacement thread and drive thread may have a different hand and/ordifferent leads. Drive thread 27 may be a double-thread. Drive thread 27and/or displacement thread 26 may be a helical thread. Drive thread 27preferably protrudes further in the radial direction from piston rod 12than displacement thread 26.

Furthermore, the drug delivery device 1 comprises a clutch member 28.The clutch member 28 is configured to be connected to the dose member23. The clutch member may be connected to the dose member 23 forfollowing movement of the dose member in the proximal direction withrespect to the housing during setting of the dose and/or in the distaldirection with respect to the housing during delivery of the dose. Thedose member 23 may rotate with respect to the clutch member 28 and, inparticular, with respect to the housing 13. The clutch member 28 issecured against (any) rotational movement with respect to the housing13. Axial movement of clutch member 28 with respect to the housing isallowed. Clutch member 28 may be a sleeve, for example. The clutchmember has an opening 29. Opening 29 may be a central opening. Opening29 is configured for the piston rod 12 to pass through opening 29 whenpiston rod 12 is displaced in the distal direction for delivering thedose. Piston rod 12 is preferably configured for being secured againstmovement in the proximal direction during setting of the dose and/orduring delivery of the dose. Accordingly, the position of a particularpoint on the piston rod with respect to the distal end of the cartridgemay be indicative for the amount of drug available in the cartridge fordelivery.

The device further comprises a stop member 30. The clutch member 28 maybe arranged to mechanically cooperate with, for example to abut, stopmember 30. Stop member 30 may define a clutch stop position for proximaldisplacement of the clutch member 28 with respect to the housing and/orwith respect to the piston rod 12. Stop member 30 may be connected to orintegrated in the piston rod 12. The position of the stop member 30 withrespect to the distal end of the cartridge 4 may be indicative of theamount of drug available in the cartridge for dispense. Stop member 30may be configured to abut a proximal face of the clutch member 28. Stopmember 30 may be formed by means of drive thread 26, in particular adistal end thereof.

Opening 29 is expediently configured to permit relative axial and/orrotational movement of the piston rod 12 with respect to the clutchmember 28 until clutch member 28 and stop member 30 may cooperatemechanically. Opening 29 extends through the clutch member 28 from itsproximal end to its distal end. Clutch member 28 comprises a main bodyportion 31, e.g. a tubular portion. Clutch member 28 comprises a flangeportion 32. Flange portion 32 protrudes radially from the main bodyportion 31. Flange portion 32 may be arranged at the proximal endsection of main body portion 31. A proximal face of flange portion 32may be configured for abutting stop member 30, in particular a distalend face thereof.

The drug delivery device may comprise a connection member 33. Theconnection member 33 may be provided for connecting the clutch member tothe dose member 23. The clutch member 28 may be firmly connected to thedose member 23 by means of connection member 33. The connection member33 has a main body portion 34, e.g. a tubular portion. The main bodyportion 34 may be adapted to be received within dose member 33.Connection member 33 may have a (central) opening 35. Piston rod 12 maytravel through opening 35. The connection member may further compriseone or more (outer) guide features 36. Guide features 36 may beconfigured for engaging guide tracks 22 of insert member 18. Relativerotational movement between connection member 33 and housing 13 may beprevented in this way. Guide features 36 may be guide pins, for example.Guide features may protrude radially from connection member 33. Guidefeatures 36 may be disposed about the perimeter of connection member 33.Connection member 33 may have a flange portion 37. Guide features 36 mayprotrude from the flange portion 37.

A proximal surface of connection member 33 may be arranged to abut adistal surface of dose member 23. Connection member 33 may comprise oneor more (inner) connection features 38, for example snap features.Connection features 38 may protrude radially inwardly within opening 35of connection member 33. Connection features 38 are expedientlyconfigured to engage one or more fixing members 39 provided in clutchmember 28. Fixing members 39 are expediently provided in the main bodyportion 31 of the clutch member 28. Fixing members 39 may be snap slots,for example. When connection member 33 is connected to clutch member 28,relative rotational movement between connection member and clutch memberis prevented. However, a proximal and a distal end stop, for exampleformed by a distal end surface and a proximal end surface of the fixingmembers 39 may limit relative axial movement between connection member33 and clutch member 28. Dose member 23 may rotate in both directionswith respect to clutch member and connection member when dose member 23is not mechanically cooperating with clutch member 28 as it wasdescribed below and is further described below.

FIG. 3 shows the clutch member 28 in more detail. Clutch member 28 hasan engagement member 40. Engagement member 40 is configured to engage anengagement feature 41 of the dose member 23 (see the more detailedillustration of dose member 23 in FIG. 4). Engagement member 40 and/orengagement feature 41 may be a toothing comprising a plurality of teeth,preferably saw-teeth. The respective toothing may be disposed about theperimeter of engagement feature 41 or engagement member 40,respectively. The teeth of the respective toothing may be orientedaxially. The teeth of engagement member 40 are disposed along theperimeter of the clutch member 28, in particular along the flangeportion 32 thereof. Engagement member 40 may be arranged on a distalsurface of the clutch member 28, in particular on a distal surface offlange portion 32. The dose member 23 may comprise a flange portion 42.Flange portion 42 may protrude radially inwardly from the dose member23. Flange portion 42 and/or engagement feature 41 may be arranged inthe distal end section of dose member 23 and/or in the threaded sectionof the dose member, i.e. that section in which thread 24 is arranged.Flange portion 42 may be arranged in the distal (end) section of dosemember 23. Teeth of the toothing of the engagement feature 41 may beconfigured to mate teeth of the toothing of engagement member 40.Thereby, dose member 23 and clutch member 28 may mechanically cooperatewith one another.

When in mechanical cooperation (mechanical interaction), in particular,when engagement feature 41 and engagement member 40 are in engagement,relative rotational movement between dose member 23 and clutch member 28is permitted only in one direction, preferably the second direction,i.e. the one in which the dose member rotates during dose delivery.Rotation of the dose member in the first direction which is necessaryfor setting of a dose is prevented on account of the engagement of dosemember 23 and clutch member 28 and, in particular, on account of theclutch member 28 being secured against rotational movement with respectto the housing 13. For example, rotation of the dose member 23 in thefirst direction may be prevented by the steep sides of the respectiveteeth abutting. Rotational movement of the dose member 23 with respectto the clutch member 28 in the second direction may be allowed due tothe beveled sides of the teeth sliding along each other. Accordingly,during mechanical cooperation, a uni-directional friction clutchmechanism may be formed between clutch member 28 and dose member 23 bymechanical cooperation of engagement feature 41 and engagement member40.

As shown in FIG. 5, the clutch member 28 is retained within andconnected to dose member 23. Connection member 33 is (firmly) connectedto clutch member 28, in particular by the connection features 38engaging fixing members 39.

The main body portion 31 of the clutch member 28 may extend from theproximal side of the opening defined by flange portion 42 to the distalside thereof. The connection member 33 may be connected to the clutchmember 28 via the main body portion 31 on the distal side of flangeportion 32. The engagement member 40 and the engagement feature 41 faceeach other. Flange portion 42 and flange portion 32 overlap.

The engagement member 40 and the engagement feature 41 are biased awayfrom one another to keep the dose member 23 and the clutch member 28 outof interaction. For this purpose, a clutch spring member 43 is providedfor (cf. FIG. 5). Clutch spring member 43 may be a (helical) coilspring, for example. Clutch spring member 43 may be a pressure spring.Accordingly, during normal operation, i.e. when clutch member 28 is outof the clutch stop position, relative rotational movement in bothdirections is permitted, because the dose member 23 and the clutchmember 28 do not mechanically cooperate with one another on account ofthe clutch spring member 43 preventing mechanical cooperation by keepingengagement member 40 at a predetermined distance from engagement feature41. Clutch spring member 43 may bear on the clutch member 28, preferablyon flange portion 32. Preferably, clutch spring member 43 is arrangedwithin a notch 44, which may be provided for in clutch member 28 toreceive an end of clutch spring member 32. Notch 44 may be provided inflange portion 32. Notch 44 may be formed between main body portion 31and engagement member 40 (see FIG. 3, for example).

For connecting the clutch member 28 to the dose member 23, at first, theclutch spring member 43 is placed on clutch member 28, in particular innotch 44. Afterwards, clutch member 28 with clutch spring member 43 isintroduced into dose member 23 until clutch spring member abuts flangeportion 42 of dose member 23, in particular radially inwardly besidesengagement feature 41. Afterwards, connection member 33 is firmly, andpreferably permanently, joined to clutch member 28. Flange portion 42 ofdose member 23 is arranged and, in particular, retained between clutchmember 28 and connection member 33.

FIG. 6 shows the dose member 23 and the connection member 33 as depictedin FIG. 5 with the (three) guide features 36 being oriented to engagethe (three) guide tracks 22 of the insert member 18. A window 45 isprovided in housing 13. Through window 45, information about a set dose,which may be provided for on a dose dial member (not explicitly shown inFIG. 6) may be made visible from outside of the housing.

FIG. 7 shows an exploded view of further parts of the drug deliverydevice 1. The drug delivery device 1 comprises a drive member 46. Drivemember 46 may be a sleeve. Drive member 46 comprises a (internal) thread47. Thread 47 may be a helical thread. Thread 47 may be adapted tocooperate with, in particular to abut, drive thread 27 of piston rod 12,preferably for putting piston rod 12 in rotation.

The drug delivery device comprises a dose dial member 48. Dose dialmember 48 may be a sleeve. The dose dial member 48 has a (outer) thread49. Thread 49 may be a helical thread. Thread 49 may determine the axialdisplacement of the dose dial member 48 in the proximal direction withrespect to the housing 13 during setting of the dose and/or in thedistal direction during delivery of the dose. Thread 49 preferably has ahigher lead than thread 24. Accordingly, when rotated by the same anglein the same direction, dose member 23 is axially displaced by a distancewhich is smaller than the distance by which the dose dial member 48 isaxially displaced. The outer surface of dose dial member 48 may beprovided with indication elements, for example numerals. The numeralsmay indicate the size of the dose which is set by a user for delivery.In particular, the indication element rotated under window 45 mayindicate the size of the dose which is dispensed when the currently setdose is delivered. The dose dial member 48 may comprise one or more(inner) guide slots 50. Dose member 23 may be splined to the dose dialmember 48, for example by the respective guide member 25 engaging acorresponding guide slot 50. Guide slots 50 expediently extend axially.

The dose part 16 comprises a dose dial part 51. The dose part 16comprises a dose button part 52. The dose dial part 51 may be rotatedwith respect to the housing 13 and, in particular, with respect to dosebutton part 52 for setting of a dose. Dose dial member 48 followsrotation of the dose dial part 51 during dose setting. The amount ofrotation, e.g. the turns made, determines the size of the dose and/orthe distance by which the dose dial member 48 is displaced in theproximal direction with respect to the housing 13.

The drug delivery device 1 comprises a coupling unit 53. Coupling unit53 couples drive member 46 and dose dial member 48 such that drivemember 46 follows rotation of the dose dial member 48 during setting ofthe dose. When the dose button part 52 is depressed for dose delivery,i.e. after the dose has been set, drive member 46 and dose dial member48 are decoupled. The decoupling may be achieved by dose button part 52interacting with coupling unit 53 when being depressed in the distaldirection with respect to dose dial part 51. Accordingly, during dosedelivery, dose dial member 48 rotates in the second direction and isdisplaced in the distal direction with respect to the housing. Drivemember is displaced in the distal direction with respect to the housingwithout rotating. Thereby, thread 47 engages and/or abuts drive thread27 of piston rod 12. Consequently, piston rod 12 rotates and isdisplaced in the distal direction with respect to the housing 13 onaccount of displacement thread 26. A similar drive mechanism isdescribed in WO 2004/078239 A1, the disclosure content of which isincorporated herein by reference for all purposes. The (proximal sectionof the) dose member 23 may be arranged between drive member 46 and dosedial member 48.

FIG. 8 shows the drug delivery device 1 in assembled condition. As shownin FIG. 8, the cartridge 4 is covered by a cap 54, which may beremovably attached to the device 1 and detached from the device foroperation of the drug delivery device 1. The piston rod 12, inparticular its displacement thread 26, is engaged with an opening 55, inparticular a threaded and/or circular opening, which is provided in thehousing 13. Accordingly, rotation of piston rod 12 results an axialdisplacement of the piston rod with respect to the housing 13. A bearingmember 56 which may be connected to piston rod 12 is arranged betweenpiston 10 and piston rod 12. The contact surface of piston rod 12 topiston 10 is increased by the bearing member. The piston rod 12 may beadapted to rotate with respect to bearing member 56. Thread 49 of dosedial member 48 engages an (inner) thread 57 of the housing 13 or aninsert thereof.

In the situation shown in FIG. 8, a dose of drug 5 to be dispensed hasbeen set by rotating dose dial member 48 in the first direction anddisplacing the dose dial member in the proximal direction with respectto the housing 13. When the dose dial member 48 is rotated, dose member23, which is splined to dose dial member 48, follows this rotationalmovement. On account of the different threads 24 and 49, dose member 23is displaced with respect to the housing 13 in the proximal direction bya distance which differs from the one the dose dial member is displaced.Preferably, dose member 23 is displaced in the proximal direction by asmaller distance than dose dial member 48. Clutch member 28 andconnection member 33 follow displacement of the dose member 23 in theproximal direction. Clutch spring member 43 prevents clutch member 28and dose member 23 from cooperating when stop member 30 is not abuttingclutch member 28. Thus, during setting of the dose, dose dial member 48and dose member 28 rotate in the first direction and are displaced inthe proximal direction for setting a dose of the drug 5 (see FIG. 9 andthe arrows therein which indicate these movements). During dose setting,dose member 23, clutch member 28 and connection member 33 are displacedin the proximal direction with respect to the housing 13 and, inparticular, with respect to the piston rod 12. Piston rod 12 remainsstationary during dose setting, i.e. at a fixed axial position. Pistonrod 12 does not rotate during dose setting. The clutch member 28 isdisplaced from a distal initial position to a proximal end positionduring dose setting with respect to the housing 13. The proximal endposition is determined by the size of the set dose. A maximum proximalend position may be determined by a maximum dose which may be set, e.g.by an end stop which limits rotation of the dose dial member 48 in thefirst direction with respect to the housing.

After the dose has been set, the dose button part 52 may be depressedand the dose may be dispensed. During delivery of the dose, piston rod12 and, of course, the stop member 30 are displaced in the distaldirection with respect to the housing 13. During dose delivery, clutchmember 28, connection member 33 and dose member 23 are moved back intothe distal initial position. Once the stop member 30 is arranged betweenthe distal initial position of the clutch member 28 and the maximumproximal end position of the clutch member 28, the clutch member 28 mayabut the stop member 30 during setting of the dose (see FIG. 10). Ifclutch member 28 and stop member 30 are in abutment, further rotation ofthe dose member 23 in the first direction moves engagement member 40 andengagement feature 41 in engagement against the force of clutch springmember 43. When in engagement, further rotation of the dose member 23with respect to the clutch member 28 and thus also with respect to thehousing 13 in the first direction is prevented on account of the clutchmember 28 being secured against rotation with respect to the housing.Consequently, dose dial member 48 is prevented from rotation withrespect to the housing 13. Thus, further rotation of the dose dialmember 48 in the first direction (the dose setting direction) which isnecessary for increasing the size of the dose is prevented. As theposition of the stop member 30 with respect to the distal end of thecartridge 4 is indicative of the amount of drug 5 remaining in thecartridge, setting of a desired dose of drug which exceeds the actuallyavailable amount of drug is prevented. However, as rotation of the dosemember 23 and, in particular, the dose dial member 48 in the seconddirection with respect to the housing 13 (the dose delivery direction)is still allowed, the set dose, i.e. the amount which was available inthe cartridge, may be dispensed and is not wasted.

The scope of protection of the invention is not limited to the examplesgiven hereinabove. The invention is embodied in each novelcharacteristic and each combination of characteristics, whichparticularly includes every combination of any features which are statedin the claims, even if this feature or this combination of features isnot explicitly stated in the claims or in the examples.

REFERENCE NUMERALS

1 drug delivery device

2 cartridge unit

3 drive unit

4 cartridge

5 drug

6 outlet

7 distal end of the device

8 proximal end of the device

9 membrane

10 piston

11 cartridge retaining member

12 piston rod

13 housing

14 proximal end of cartridge unit

15 distal end of housing

16 dose part

17 proximal end of housing

18 insert member

19 fixing member

20 guide member

21 thread

22 guide track

23 dose member

24 thread

25 guide member

26 displacement thread

27 drive thread

28 clutch member

29 opening

30 stop member

31 main body portion

32 flange portion

33 connection member

34 main body portion

35 opening

36 guide feature

37 flange portion

38 connection feature

39 fixing member

40 engagement member

41 engagement feature

42 flange portion

43 clutch spring member

44 notch

45 window

46 drive member

47 thread

48 dose dial member

49 thread

50 guide slot

51 dose dial part

52 dose button part

53 coupling unit

54 cap

55 opening

56 bearing member

57 thread

1-15. (canceled)
 16. An assembly for a drug delivery device, comprising:a housing having a proximal end and a distal end; a dose member which isdisplaceable in the proximal direction with respect to the housing forsetting of a dose of a drug; a clutch member which is displaced in theproximal direction with respect to the housing when setting the dose;and a stop member configured to define a clutch stop position for theproximal displacement of the clutch member with respect to the housing,with the clutch member, when in the clutch stop position, beingprevented from further displacement in the proximal direction withrespect to the housing, wherein the clutch member and the dose memberare configured to mechanically cooperate with one another when theclutch member is in the clutch stop position, thereby preventing furtherdisplacement of the dose member in the proximal direction with respectto the housing during setting of the dose.
 17. An assembly according toclaim 16, wherein the dose member is threadedly connected to the housingand wherein the dose member is rotated in a first direction with respectto the housing and displaced in the proximal direction with respect tothe housing for setting of the dose.
 18. An assembly according to claim17, wherein rotation of the dose member in the first direction withrespect to the housing for setting of the dose is prevented or stoppedwhen the dose member and the clutch member cooperate mechanically. 19.An assembly according to claim 16, wherein, during mechanicalcooperation of the dose member and the clutch member, rotationalmovement of the dose member with respect to the clutch member in thefirst direction is prevented, whereas rotational movement of the dosemember with respect to the clutch member in a second direction oppositeto the first direction is allowed.
 20. An assembly according claim 16,wherein the clutch member follows displacement of the dose member in theproximal direction with respect to the housing during setting of thedose.
 21. An assembly according to claim 16, wherein the clutch memberis connected to the dose member.
 22. An assembly according to claim 16,which comprises a piston rod configured to be displaced in the distaldirection with respect to the housing for delivering the dose.
 23. Anassembly according to claim 22, wherein the stop member is integrated inor connected to the piston rod.
 24. A drug delivery device, comprisingan assembly according to claim 16 and a cartridge containing the drug.25. A drug delivery device according to claim 24, wherein the cartridgehas a proximal end and a distal end, a piston is retained within thecartridge, the piston being displaceable in the distal direction withrespect to the cartridge for dispensing a dose of the drug from thecartridge.